【作者】 王阳；

【导师】 柳明珠；

【作者基本信息】 兰州大学 ， 化学·高分子化学与物理， 2017， 博士

【摘要】 将高分子与无机纳米粒子进行复合,构建的电化学生物传感器,可以结合高分子生物相容性好、稳定性高、选择性优良,和无机纳米粒子比表面积大、电化学活性强的优势,对提高传感器的性能有着巨大的意义。本论文基于高分子-无机纳米粒子制备出一系列具有优良导电性和高电化学催化活性的复合材料,进而构建出多种电化学生物传感器,用于多巴胺和葡萄糖的电化学检测。采用透射电子显微镜（TEM）、扫描电子显微镜（SEM）、红外光谱（FTIR）、X-射线衍射（XRD）、X-射线光电子能谱（XPS）、循环伏安法（CV）、脉冲伏安法（DPV）、计时电流法（i-t）等对所得传感器的结构、形貌及性能进行了研究。具体研究内容及结果如下:（1）PPy/Fe₃O₄及Fe₃O₄@MOFs修饰的石墨烯复合材料用于构建多巴胺电化学传感器将对甲苯磺酸（p-TSA）掺杂的聚吡咯（PPy）纳米微球修饰在还原的氧化石墨烯纳米片（rGO）上,首先用溶剂热法制备了Fe₃O₄/rGO,之后利用吡咯单体在Fe₃O₄纳米粒子表面聚合,以p-TSA作为掺杂剂,反应得到doped-PPy/Fe₃O₄/rGO复合材料。此外,利用锌离子MOFs（ZIF-8）在Fe₃O₄/rGO表面自组装,制备得到Fe₃O₄@ZIF-8/rGO。利用它们对玻碳电极表面进行改性,得到两种新型的多巴胺电化学生物传感器,doped-PPy/Fe₃O₄/rGO/GCE对多巴胺检测的线性范围为7×10-9²×10^-6 M,检出限为2.33×10-9 M（S/N=3）;Fe₃O₄@ZIF-8/rGO/GCE对多巴胺检测的线性范围为2.0×10-9¹.0×10^-5,检出限为6.67×10-10 M（S/N=3）。它们同样对多巴胺有良好的选择性,可以在抗坏血酸和尿酸的存在下进行实验,在实际样品中也有良好的检测性和可靠性。（2）Fe₃O₄/PPy@MOFs纳米复合材料用于构建葡萄糖电化学传感器在酸性条件下,利用吡咯单体在Fe₃O₄纳米粒子表面聚合,得到Fe₃O₄/PPy磁性纳米复合粒子,再将MOFs（ZIF-8）通过自组装作用结合在PPy表面,得到一种具有大的比表面积和良好导电性的磁性纳米复合材料,Fe₃O₄/PPy@ZIF-8。得益于MOFs优异的比表面积和孔体积,可以将葡萄糖氧化酶（GOx）高效的固定在该复合材料上,用于构建葡萄糖电化学生物传感器。改性电极后,得到的GOx/Fe₃O₄/PPy@ZIF-8/GCE传感器对葡萄糖有着非常灵敏的电化学响应性,有着宽的检测线性范围(1×10^-62×10^-3 M)和低的检出限(0.33×10^-6 M),也可对实际样品中的葡萄糖进行检测。（3）聚多巴胺/MOFs复合微囊用于构建葡萄糖电化学传感器利用模拟酶ZIF-8与葡萄糖氧化酶（GOx）组成的多酶体系构建新型葡萄糖电化学生物传感器。以CaCO3微球为模版制备的聚多巴胺（PDA）/ZIF-8生物微囊,既可以作为高效无毒的载体固定化GOx,也因ZIF-8而具有过氧化氢模拟酶的性质。将rGO结合在PDA/ZIF-8生物微囊上以加快电子在微囊与电极之间的传递速度。改性电极后,得到的GOx/PDA/ZIF-8@rGO/GCE传感器对葡萄糖有着优异的检测性能,检测的线性范围有两段,分别为1×10^-61.2×10^-3 M和1.2×10^-33.6×10^-3 M。此外,复合微囊对固定的葡萄糖氧化酶有很好的保护作用,增加了该传感器的稳定性和重复使用性能,对实际样品中葡萄糖的检测结果也较为准确。（4）电沉积Mn₂O₃/Ni（OH）₂修饰SPI/rGO膜用于构建葡萄糖电化学传感器在磺化聚酰亚胺/石墨烯（SPI/rGO）复合膜上,电沉积Mn₂O₃/Ni（OH）₂合金纳米复合材料,得到无酶的葡萄糖电化学传感器,SPI/rGO-Mn₂O₃/Ni（OH）₂。首先,使用脉冲-可逆电位法,将Mn₂O₃纳米棒电沉积在SPI/rGO复合膜上,再将Ni（OH）₂纳米粒子也电沉积在膜表面,得到SPI/rGO-Mn₂O₃/Ni（OH）₂。得益于Mn₂O₃/Ni（OH）₂高效的电化学催化活性和SPI/rGO复合膜优良的导电性和电子传递能力,制备得到的无酶葡萄糖电化学传感器有着优异的检测性能。加之高分子复合膜出色的稳定性,增加了传感器的重复使用性能,长期存放后,依然对葡萄糖溶液可进行准确检测。更多还原

【Abstract】 Taken the advantage of good biocompatibility,high stablility and good selectivity from polymer and large specific surface area and strong electrocatalytic activity from inorganic nanoparticles,the polymer-inorganic nanoparticle composites could show great significance in fabrication of electrochemical biosensor.Consideration of this,in this dissertation,a series of electrochemical biosensors based on polymer-inorganic conductive composites were prepared through the combination of conductive polymer with inorganic nanomaterials.Several techniques were used to study their structures,morphologies and properties,such as the transmission electron microscopy（TEM）,scanning electron microscopy（SEM）,FTIR,X-ray diffraction spectrometry（XRD）,X-ray photoelectron spectroscopy（XPS）,cylic voltammetry（CV）,etc.The main contents and results of this dissertation were summarized as follows:（1）Ultrasensitive electrochemical sensing of dopamine using p-TSA doped polypyrrole/Fe₃O₄ or Fe₃O₄@MOFs nanocomposites decorated reduced graphene oxide sheetsA hybrid nanocomposite consisting of polypyrrole（PPy）nanospheres doped with p-toluenesulfonate（p-TSA）was prepared and deposited on sheets of reduced graphene oxide（rGO）.The rGO sheets were first coated with Fe₃O₄ particles,and pyrrole was then polymerized on their surface to obtain architecture of the type PPy/Fe₃O₄/rGO.Addition of p-TSA during polymerization led to the formation of p-TSA-doped PPy to obtain doped-PPy/Fe₃O₄/rGO.Moreover,the MOFs（ZIF-8）were coated on the surface of Fe₃O₄ to get the Fe₃O₄@ZIF-8/rGO nanocomposite.Two kinds of nanocomposites were placed on a glassy carbon electrode to give an electrochemical sensor（doped-PPy/Fe₃O₄/rGO/GCE and Fe₃O₄@ZIF-8/rGO/GCE）for dopamine（DA）,respectively.Both sensors have a wide linear range,a low detection limit,and good selectivity for DA over ascorbic acid and uric acid.It also gave satisfactory results in the determination of DA in spiked samples of urine and serum.（2）Preparation of magnetic Fe₃O₄/PPy@MOFs nanocomposite for glucose oxidase immobilization and used as glucose electrochemical biosensorThe MOFs（ZIF-8）coated Fe₃O₄/PPy magnetic nanocomposite（Fe₃O₄/PPy@ZIF-8）,with large surface area and high conductivity,was prepared by polymerizing the pyrrole on Fe₃O₄ nanoparticle and self-assembling the ZIF-8 on the obtained magnetic Fe₃O₄/PPy.Due to the outstanding specific area and pore volume of MOFs,the glucose oxidase（GOx）can be effectively immobilized on the Fe₃O₄/PPy@ZIF-8 to fabricate a potentiometric glucose biosensor.The as-prepared GOx/Fe₃O₄/PPy@ZIF-8/GCE biosensor exhibited extraordinary electro-detection performance for glucose with wide linear range from 1×10^-6 M to 2×10^-3 M and the limit of detection was 0.33×10^-6 M（S/N=3）.Furthermore,the prepared biosensor also showed good selectivity for glucose detection and satisfactory result in real samples detection.（3）Preparation of graphene nano-sheets bonded PDA/MOFs microcapsules immobilized glucose oxidase as mimetic multi-enzyme system for electrochemical sensing of glucoseA novel amperometric biosensor for glucose detection was fabricated based on the mimetic multi-enzyme system by combing the mimetic enzyme（metal-organic frameworks,MOFs）and glucose oxidase（GOx）.The microcapsule constructed with polydopamine（PDA）and ZIF-8 using CaCO3 templates could be utilized not only to provide the biocompatible and non-toxic microenvironment to immobilized GOx,but also as the efficient mimetic enzyme because of the peroxidase-like property of ZIF-8.The reduced graphene nano-sheets（rGO）were bonded to PDA/ZIF-8 microcapsules to accelerate the electron transfer between microcapsule and electrode.The mimetic multi-enzyme system was fabricated when GOx was immobilized in the as-prepared microcapsule,and the developed GOx/PDA/ZIF-8@rGO/GCE biosensor exhibited extraordinary electro-detection performance for glucose with two wide linear ranged from 1×10^-6 M to 1.2×10^-3 M and 1.2×10^-3 M to 3.6×10^-3 M.Moreover,the good selectivity for glucose and satisfactory results in real samples detection by the prepared biosensor were also demonstrated.（4）Mn₂O₃/Ni（OH）₂ electro-deposited graphene nano-sheets/ sulfonated polyimides membrane for electrochemical sensing of glucoseA novel nonenzymatic glucose sensor was fabricated based on the Mn₂O₃/Ni（OH）₂ alloy nanocomposite electro-deposited sulfonated polyimides/graphene nano-sheets membrane（SPI/rGO）.Firstly,Mn₂O₃ nanorod array was prepared on SPI/rGO membrane using pulse reverse potential electrodeposition.Then Ni（OH）₂ nanoparticle was also deposited on the membrane to get SPI/rGO-Mn₂O₃/Ni（OH）₂.The electrochemical behaviors of resulted sensor were investigated by cyclic voltammetry and chronoamperometry in alkaline solution.Combination the outstanding electrocatalytic activity of Mn₂O₃/Ni（OH）₂ and high conductivity of SPI/rGO,the resulted sensor showed remarkable advantages for glucose detection,the linear range of detection was from 1×10^-6 M to 1.8×10^-3 M.Other detection performance of the prepared biosensor,like high sensitivity,long-term stability and reproducibility were also demonstrated.更多还原